|Been et al. Figure , illustrating calculation of lordotic angle|
In a new study just up on AJPA early view, Been and colleagues report on a study of lumbar spinal curvature (lumbar lordosis) in fossil hominins. Previous studies had relied on the degree of wedging of lumbar vertebrae to estimate the degree of lumbar curvature. The new study introduces a method "based on the relationship between the lordotic curvature and the orientation of the inferior articular processes relative to vertebral bodies in the lumbar spines of living primates" (Been et al., AJPA).
The study finds that australopiths had a nearly modern-human like degree of lordosis, supporting the notion of lumbar lordosis as a morphological adaptation to habitual bipedalism. The study also tentatively suggests locomotor differences between Neanderthals and modern humans based on degree of lumbar curvature.